How do low oxygen levels affect aquatic ecosystems?
Dissolved oxygen levels affect the survival of aquatic organisms. Trout and the nymphs of mayflies or stoneflies are found only in water with high oxygen concentrations. If dissolved oxygen levels are low, only organisms such as leeches, snails and roundworms can survive. Fish and stonefly nymphs die while trapped in water with decreased oxygen levels. Low levels of dissolved oxygen can result in significant fish kills, especially in late summer or during the winter.
